Method for manufacturing fan blade and fan using such fan blades

ABSTRACT

A method for manufacturing a fan blade includes the steps of, firstly, providing a mold. Then a mixture of metal powder and adhesive material is injected into the mold to forming a green body of the blade. Next, the adhesive material is removed from the green body of the blade. Finally, the green body of the blade is sintered to form the fan blade. A fan with such blades is also provided.

BACKGROUND

1. Technical Field

The present disclosure relates to methods for manufacturing fan blades, and to fans using fan blades.

2. Description of Related Art

Generally, cooling fans are used in combination with heat sinks for cooling electronic components, such as central processing units (CPUs). Most portable electronic systems that contain electronic components, such as laptop computers and notebook computers, have limited space therein. Thus a fan which requires only a small space for installation is generally used in such electronic systems.

Generally, an impeller of a fan comprises a plurality of blades which are made of polybutylene terephthalate (PBT). In order to improve the cooling and heat dissipation efficiency of a fan, the most direct and effective way is to increase the revolving speed of the impeller, thereby increasing the flow rate of the airflow produced by the fan. However, when the impeller of the fan has PBT blades, increasing the flow rate by increasing the rotating speed of the impeller generally causes the level of noise to be increased. In addition, the PBT blades are liable to distort after a long service time working at high temperatures, thereby diminishing the cooling properties of the fan.

What is needed, therefore, is a fan blade which can overcome the above-described problems.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present method and fan can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present method and fan. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an assembled, isometric view of a fan in accordance with an embodiment of the disclosure.

FIG. 2 is an exploded view of the fan of FIG. 1.

FIG. 3 is an inverted view of the fan of FIG. 2.

FIG. 4 is a top plan view of a base plate and an impeller of the fan of FIG. 2.

DETAILED DESCRIPTION

Referring to FIG. 1, a fan 10 in accordance with an embodiment of the disclosure includes a housing 100 and an impeller 200 rotatably received in the housing 100. The fan 10 is configured to generate an airflow for heat dissipation of an electronic component (not shown).

Referring also to FIGS. 2 and 3, the housing 100 includes a base plate 110, a covering plate 120 located above the base plate 110, a peripheral sidewall 130 extending downwardly from an outer periphery of the covering plate 120, and a connecting flange 140 formed at the outer periphery of a bottom of the sidewall 130. The sidewall 130 is located between the base plate 110 and the covering plate 120. The connecting flange 140 protrudes outwardly from a bottom edge of the sidewall 130, and is positioned adjacent to the base plate 110 and tightly attached to the base plate 110. In this embodiment, the covering plate 120, the sidewall 130 and the connecting flange 140 are integrally formed as a single monolithic piece of the one same material. The base plate 110, the covering plate 120, and the sidewall 130 cooperatively define a receiving space 150 therebetween, for receiving the impeller 200.

A first air inlet 121 is defined in the covering plate 120. The first air inlet 121 is circular, and is defined at a center of the covering plate 120. A second air inlet 111 is defined at a center of the base plate 110. The first air inlet 121 and the second air inlet 111 are configured to provide air for the fan 10. Ends of the base plate 110, the covering plate 120 and the sidewall 130 cooperatively define a rectangular air outlet 16 located at a lateral side of the housing 10.

A first ledge 141 is formed at one end of the connecting flange 140. The first ledge 141 includes a circular through hole 142, and a clasp 143 extending downwardly to the base plate 110 and further extending downwardly below the base plate 110. A second ledge 112 is formed at the base plate 110 in a position corresponding to the first ledge 141. The second ledge 112 include a circular through hole 113 corresponding to the through hole 142, and a groove 114. The connecting flange 140 includes a plurality of other clasps 143 extending downwardly to the base plate 110 and further extending downwardly below the base plate 110. A plurality of other grooves 114 are defined at a periphery of the base plate 110. All of the clasps 143 are engaged in all of the grooves 114, respectively. A screw (not shown) is passed through the through hole 142 and the through hole 113 to further connect the base plate 110 with the connecting flange 140.

The impeller 200 includes a hub 210, a supporting element 220 surrounding and rotatably connected to the hub 210, and a plurality of blades 230 extending outwardly from the supporting element 220.

Referring also to FIG. 4, the supporting element 220 includes a plurality of connecting arms 221 extending outwardly from the hub 210, and a fixing ring 222 formed at outer ends of the connecting arms 221. The fixing ring 222 encircles the hub 210, and the blades 230 are arranged on the fixing ring 222. Each of the blades 230 has a curved structure, such as an arc-shaped structure, and is perpendicular to the fixing ring 222. An inner end of each of the blades 230 defines a horizontal groove 231 therein. The groove 231 can interferingly receive the fixing ring 222 therein, so that the blade 230 is secured to the fixing ring 222. In this embodiment, the blades 230 are made of metal, and are formed by a metal injection molding technique. The blades 230 surround the hub 210 and are positioned on the fixing ring 222 at predetermined uniform intervals. The blades 230 have a thickness less than 0.5 mm (millimeters). Preferably, the blades 230 have a thickness less than 0.3 mm. In operation of the fan 10, air flows into the fan 10 via the first air inlet 121 and the second air inlet 111 under impetus of rotation of the blades 230, and flows out of the fan 10 through the air outlet 134, therefore providing airflow for heat dissipation of the electronic element.

The method for manufacturing the blades 230 is described in detail below.

A mold is firstly provided. In one embodiment, the mold is configured for making a plurality of the blades 230. A mixture of metal powder and adhesive material is then injected into the mold to form a plurality of green bodies of the blades 230. The metal powder is selected from a group consisting of stainless steel, copper, titanium and alloys thereof. The adhesive material is selected from a group consisting of olefin, polyethylene, and polypropylene. Preferably, a ratio of a weight of the adhesive material to a weight of the metal powder is in the range of from 0.07 to 0.1.

The adhesive material in the green bodies of the blades 230 is then removed by degreasing techniques or extraction techniques.

After the adhesive material is removed, the green bodies of the blades 230 are sintered to obtain the blades 230 with a high density and high intensity. Generally, the green bodies of the blades 230 can be sintered in a vacuum environment, an oxygen atmosphere or a nitrogen atmosphere. A sintering temperature of the green bodies of the blades 230 is in the range of from 800 degrees Centigrade to 1500 degrees Centigrade.

After sintering, the green bodies of the blades 230 are constringed and need to be finished. The finishing technique of the blades 230 can be selected from broach dressing, bit dressing, grinding, and CNC (Computerized Numerical Control) lathe processing. Alternatively, the finishing of the blades 230 can be by chemical etching or electrolytic discharging. The finally finished blades 230 are then attached on the fixing ring 222 to form the impeller 200.

In the fan 10 described above, the blades 230 are made of metal and formed by a metal injection molding technique. Therefore, the blades 230 can have a thickness less than that of conventional PBT blades. For example, PBT blades generally have a thickness of about 0.6 mm. In contrast, the blades 230 have a thickness less than 0.5 mm, or even less than 0.3 mm. As such, the fan 10 can provide a large airflow and improved heat dissipating efficiency.

In addition, since the blades 230 are made of metal, the intensity of the blades 23 is enhanced. In particular, the blades 230 do not easily distort when the fan 10 is operating at high speed; therefore the fan 10 can operate stably, effectively and reliably.

It is to be understood, however, that even though numerous characteristics and advantages of various embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

What is claimed is:
 1. A method for manufacturing a fan blade, comprising: providing a mold; injecting a mixture of metal powder and adhesive material into the mold and forming a green body of the blade; removing the adhesive material from the green body of the blade; and sintering the green body of the blade to form a fan blade.
 2. The method of claim 1, wherein a material of the blade is selected from the group consisting of stainless steel, cooper, titanium and alloys thereof.
 3. The method of claim 1, wherein the adhesive material is selected from the group consisting of olefin, polyethylene, and polypropylene.
 4. The method of claim 1, wherein a ratio of a weight of the adhesive material to a weight of the metal powder is in a range of from 0.07 to 0.1.
 5. The method of claim 1, wherein the green body of the blade is sintered at a temperature in the range of from 800 degrees Centigrade to 1500 degrees Centigrade.
 6. The method of claim 1, wherein the green body of the blade is sintered in one of a vacuum environment, an oxygen atmosphere, and a nitrogen atmosphere.
 7. The method of claim 1, wherein the blade after sintering has a thickness of less than 0.5 mm.
 8. The method of claim 1, wherein the blade after sintering has a thickness of less than 0.3 mm.
 9. A fan, comprising: a housing defining a receiving space therein; and an impeller received in the housing, the impeller comprising a hub, a supporting element rotatably fixed around the hub, and a plurality of blades extending outwardly from the supporting element; wherein each of the blades is a sintered metal powder blade.
 10. The fan of claim 9, wherein the housing comprises a base plate, a covering plate located above the base plate, and a sidewall extending downwardly from an outer periphery of the covering plate, a first air inlet is defined at a center of the covering plate, and a air outlet is defined by the base plate and the covering plate at a lateral side of the housing.
 11. The fan of claim 10, wherein a second air inlet is defined at a center of the base plate.
 12. The fan of claim 10, wherein a connecting flange is formed at one end of the covering plate and tightly attached to the base plate, and the covering plate, the sidewall and the connecting flange are integrally formed as a single monolithic piece of the one same material.
 13. The fan of claim 10, wherein the supporting element comprises a plurality of connecting arms extending outwardly from the hub, and a fixing ring formed at outer ends of the connecting arms, the fixing ring encircles the hub, and the blades are arranged on the fixing ring.
 14. The fan of claim 13, wherein each of the blades defines a groove at one end thereof to clamp with the fixing ring.
 15. The fan of claim 10, wherein a material of the blade is selected from a group consisting of stainless steel, cooper, titanium and alloys thereof.
 16. The fan of claim 10, wherein each of the blades has a thickness of no more than 0.5 mm.
 17. The fan of claim 10, wherein each of the blades has a thickness of no more than 0.3 mm. 